1. Technical Field
The present invention relates to a light emitting device which emits light by electro Luminescence and an electronic apparatus.
2. Related Art
As a thin lightweight light emitting source, an OLED (Organic Light Emitting Diode), that is, an organic EL (Electroluminescent) element has been popular. Accordingly, an image display apparatus including a plurality of the organic EL elements has been developed. The organic EL element has a configuration in which at least one organic thin film layer made of an organic material is interposed between pixel electrodes and counter electrodes.
In a field of the organic EL element, there is known a technique (for example, a PCT pamphlet No. WO01/39554) for intensifying light having a specific wavelength among emitted light by use of amplified interference, that is, resonance. This technique is capable of increasing color purity of a luminescent color or improving efficiency of light emitted in response to light emission.
However, in order to effectively achieve the improvement in the color purity by use of the resonance, a problem with an increase in an absolute amount of light associated with the resonance or an increase in reflectivity of two reflection layers provided in order to realize the resonance has to be solved.
In order to solve this problem, a method of increasing the thickness of the reflection layer can be taken into consideration. However, since at least one of the two reflection layers needs to have a light reflection feature and a light transmission feature, the method of increasing the thickness of the reflection layer (even though reflectivity is expected to be improved) may result in decreasing an amount of transmitting light. In this case, since the image display apparatus may display a relatively darker image, a new problem with image deterioration may occur.